I've got a little (well he's huge for a Port) 7" Port Cichlid I named "Fatty" that pretty much rules my 150. He's in with a big Oscar, 10" Severum, a ~22" clown knife who is particularly grumpy, and some other big fish including a Tiger Shovelnose that's probably already big enough to eat him if it really wanted to.
He stays cool as long as nobody invades his turf and everybody shows him respect in passing, and he doesn't mess with my hands or anything in the tank, but he goes berserk and bites the crap out of the algae scrubber every time I use it, it's pretty funny. The rest of the fish are terrified of it.
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